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Lake Creek Dam Updates

The run of the river dam was built in 1917. Photos by Kristin Burge

Tucked away just outside of Troy, Montana, is NLI’s Lake Creek Hydroelectric Dam. The dam was built in 1917 for a lumber mill and has seen several improvements over the years. Many of the original structures have been well-maintained and are still in use today. However, others have been replaced.

The hydroelectric dam consists of a concrete gravity dam with a penstock that drops the water downhill to 2 powerhouses that generate electricity. In terms of hydroelectric dams in the region, it is small, generating less than 2% of the output of a dam the size of Cabinet Gorge Dam by Noxon, Montana.

Crews test generation unit #2 at Lake Creek Dam.

For the past 3 years, NLI has worked on a project to upgrade and replace portions of the larger generator unit. This includes remanufacturing the large turbine and other components. The old turbine was more than 40 years old.

Due to the need to disassemble and remove portions of the generating unit, power generation has been offline at Lake Creek Dam since August 2023. During that time, NLI completed several projects, including dredging the reservoir.

NLI Engineering Intern Erika Edmundson measures sediment levels.

Lake Creek Dam is a run-of-river dam, meaning NLI does not store any water to release at scheduled times or to hold for later in the summer. The water flow is the natural flow of Lake Creek, which is fed primarily from Bull Lake and other small creeks. Sediment built up behind the dam to the point it was entering the penstock. This was verified while disassembling the generator unit and observing excessive wear and sediment deposits.

Sediment buildup is not unique to Lake Creek Dam, as many other dams experience the same issue due to the change in the natural flow of water. Dredging is complete, and sediment should not be a problem for years to come.

NLI plans to have the generation back online around the beginning of November. The new turbine is installed, and final testing was at the end of October. These upgrades will provide NLI’s members with local hydropower generation for many years.